Help me write a formal Japanese email?

So although I can speak Japanese fairly well, my keigo is, unfortunately, a little dismal. I am compiling a documentary of sorts in Japan for the next few months, and I'm writing emails to see if I can secure some interviews. Would you please look at my replies and make sure they are proper keigo and that the sentence structure is good?

The email I received was asked if I had a budget to dedicate to the interview. I want to reply: "Thanks for the email. I have a budget, but since my college is small, so is my budget. I am planning to see the performance at Gion Corner, but aside from that I can only pay 2000 or 3000 yen. I'm sorry -- I know it's not much. My Japanese is not fluent, but I can ask my questions in Japanese if that is more convenient for you."

メールを送って下さってありがとうございました。

予算がありますが、大学は大きくないので、予算も大きくないです。ギオンコーナーの公演をお見するつもりです。この以外に二千円か三千円しかお払えします。少ないで申し訳ありません。私は日本語でペラペラではないですが、日本語で質問をお聞きできます。

So that is the first one. The second email (from another place) just asked me when and what time I would show up, and I want to say "I can arrive whenever is convenient for you. I think that the end of September or beginning of October would be best." For some reason, I'm having a hard time formulating that in Japanese. In addition to checking my Japanese above, would you be so kind as to translate that for me?

Thanks so much for help, whoever decides to actually read all this! :)